A conventional fuel injection valve is provided with components such as a needle, a control chamber and an electromagnetic valve. The needle opens and closes an injection hole for injecting fuel to an internal combustion engine (engine). The control chamber is introduced with high-pressure fuel. The electromagnetic valve opens and closes a discharge passage which discharges fuel in the control chamber to an externally located low pressure area. When the electromagnetic valve closes the discharge passage, fuel in the control chamber urges the needle to close the injection hole. When the electromagnetic valve opens the discharge passage, fuel in the control chamber is discharged and permits the needle to open the injection hole. One of this kind of fuel injection valve is disclosed in JP2002-147310A.
The fuel injection valve includes a housing which is disposed next to the solenoid of the electromagnetic valve and is disposed on a side of the solenoid opposite to the needle. The housing includes a lower hole, an upper hole, and a communicating hole. The lower hole provides a part of the discharge passage. The upper hole is disposed in the downstream of the lower hole and provides a part of the discharge passage. The communicating hole provides a part of the discharge passage by communicating the lower hole and the upper hole. A spring which pushes and urges an armature and a movable member for a valve is arranged in the lower hole. A return pipe for leading fuel discharged from the control chamber to the low pressure area, e.g., a fuel tank is inserted in the upper hole. The armature is also arranged in the discharge passage.
The lower hole includes a bottom which works as a spring seat. For this reason, it is necessary to form an inner diameter of the communicating hole smaller than an outer diameter of the spring. For example, the inner diameter of the communicating hole may be formed substantially equal to the inner diameter of the spring.